Air supply device for air heating and cooling system

ABSTRACT

A two-stage blower is driven by a liquid-cooled engine. The first stage of the blower operates in a chamber divided from an intake plenum for the second stage by an orifice plate. For heating, a starvation damper for the first stage chamber is opened, heat is added to the air and its potential energy is reduced to substantially zero by the orifices which the air passes through to the second stage. For cooling, the starvation damper is closed, the first stage runs idle, and intake air for the second stage is drawn directly from the atmosphere to the second stage.

United States Patent Shepheard [451 Oct. 17, 1972 54 AIR SUPPLY DEVICE FOR AIR 3,219,027 11/1965 Roche ..126/247 HEATING AND COOLING SYSTEM 3,333,771 8/1967 Graham ..126/247 [72] Inventor: Wilson C. Shepheard, PO. Box

7245, Norfolk, Va. 23609 22] Filed: -0c1.12, 1970 [21] Appl. No.: 79,930

[52] U.S.Cl ..415/115,415/l45,4l5/199R [51] Int. Cl ..F0ld 5/14 [58] Field ofSearch....4l5/ll5,145,199 R; 126/247 [56] References Cited UNITED STATES PATENTS 1,034,894 8/1912 Fisker ..415/199 R 2,189,162 2/1940 Buck et a1 ..415/145 1,561,847 11/1925 Green ..415/199 R 2,285,338 6/1942 Kidney ..415/199 R 2,604,501 7/1952 Wightman ..415/199 R Primary Examiner-C. J. Husar AttorneyJames H. Littlepage [57] ABSTRACT A two-stage blower is driven by a liquid-cooled engine. The first stage of the blower operates in a chamber divided from an intake plenum for the second stage by an orifice plate. For heating, a starvation damper for the first stage chamber is opened, heat is added to the air and its potential energy is reduced to substantially zero by the orifices which the air passes through to the second stage. For cooling, the starvation damper is closed, the first stage runs idle, and intake air for the second stage is drawn directly from the atmosphere to the second stage.

1 Claim, 1 Drawing Figure PATENTEDnm n m 3,698,831

INVENTOR ATTORN WILSON C. SHEPHEARD- AIR SUPPLY DEVICE FOR AIR HEATING AND COOLING SYSTEM PRIOR ART Allen US. Pat. No. 1,682,102; Hokanson, Sr. et a]. U.S. Pat. No. 3,481,322

OBJECTS The object of this invention is to improve the efficiency of the heating phase of a combined air heating andcooling unit, for example, of the type mounted on a fle S0 in working chamber defines between it and orifice plate 46 an intake plenum 52 for working chamber ble bearings 64 rotatably support drive shaft 36in castruck chassis and used for heating or cooling the interior of aircraft. Until recently, these mechanisms were usually provided with heaters of various types which not only were expensive, but which also failed to utilize the heat energy available from the engine which drives the blower for the air which was forced into the aircraft. Now, however, it is intended to provide an extremely simple mechanism, easily shiftable between heating and cooling modes, and closely approaching 100 percent efficiency when operated in the heating mode. To this end there is provided a two-stage blower operable in either of two modes for supplying either heated or substantially unheated air, and shiftable between the two modes simply by controlling a damper for the air intake for the first stage.

Other objects will be apparent from the following specification and drawing, in which the sole figure is a diagram of the essential parts of the system.

Referring now to the drawing, an air supply duct 2 is provided for feeding hot or cold air to a space, such as the interior of an aircraft. The supply air passes through a heat exchanger 4 which is the evaporator of a refrigerant system, and another heat exchanger 6,

' which functions as a radiator for the coolant of an internal combustion engine. One or the other of heat exchangers 4 or 6 is active, depending upon whether the system is to operate in heating or cooling mode. Engine 8 has a drive shaft 10 connectable by a clutch 12 to the pump 14 which feeds refrigerant through a circuit 16 running through a condenser 18 and the evaporator-heat exchanger 4, all being conventional components of an air cooling system, the various valves and controls for which are not shown because they are well known. Obviously, heat exchangers 4 and 6 can be combined into one unit.

Engine 8 also has a fan 20 which forces air through a radiator 22 for the engine coolant. By adjustment of valves 24, 26 the engine coolant may be circulated through radiator 22, or alternatively, via circuit 28 through heat exchanger 6. Mechanical power is derived from engine 8 by means of a belt 30 running over a pulley 32 on the engine drive shaft 10 and a pulley 34 on the drive shaft 36 of a two stage blower 38, with which the invention is concerned.

Blower 38 comprises a casing 40 having two working chambers 42 and 44 separated by an orifice plate 46 having a series of orifices 48 near its outer edges. A bafhen the system 18 operated in heating mode, the refrigerating circuit is disabled, valves 24, 26 are adjusted so as to circulate engine coolant through heat exchanger 6', and'starvation damper 58 is opened. Air drawn in through intake port 56 is compressed, i.e., work is imparted to the air mass, and the act of compression adiabatically raises the temperature of the air mass. The temperature rise is roughly equal to the BTU value of the horsepower of the work. This work is negated by forcing the air through theorifices, and the potential energy which was added to the air mass in the first stage is reduced to near zero. The air supplied by the first stage is sufficient to meet the demands of the second stage and, ideally, the pressure within the intake plenum 52 is atmospheric pressure, or nearly so, so that little if any air moves through ports 54.

For operating in the cooling mode, the'refrigerating system is activated, valves 24, 26 adjusted so as to feed the engine coolant through radiator 22 rather than heat exchanger 6, and starvation damper 58 is closed. Since blower 62 is then imparting very little work to the air trapped within chamber 42, only a small amount of heat is generated. This heat, which enters the second stage by conduction, represents only about ten percent of the heat generated when the starvation damper is open constitutes an acceptable penalty in view of the over-all efficiency and simplicity of the system.

I claim: 1. An air supply device comprising a casing having an interior defined by side walls and opposite end walls, an orifice plate extending from side wall to side wall and disposed between the end walls and dividing the casing interior into first and second chambers, first and second impellers rotatably mounted in said first and second chambers, respectively, means for driving said impellers, said second chamber having an air delivery outlet disposed for receiving air from the second impeller and having port means for introducing air from the atmosphere to the second impeller, said first chamber having an air inlet for introducing air from the atmosphere to the first impeller, and a damper for regulating said air inlet, said impellers being centrifugal blowers, the air delivery outlet for the second chamber being through a side wall of the casing, the air inlet for the first chamber being through an end wall of the casing and registering with the hub portion of the first impeller. 

1. An air supply device comprising a casing having an interior defined by side walls and opposite end walls, an orifice plate extending from side wall to side wall and disposed between the end walls and dividing the casing interior into first and second chambers, first and second impellers rotatably mounted in said first and second chambers, respectively, means for driving said impellers, said second chamber having an air delivery outlet disposed for receiving air from the second impeller and having port means for introducing air from the atmosphere to the second impeller, said first chamber having an air inlet for introducing air from the atmosphere to the first impeller, and a damper for regulating said air inlet, said impellers being centrifugal blowers, the air delivery outlet for the second chamber being through a side wall of the casing, the air inlet for the first chamber being through an end wall of the casing and registering with the hub portion of the first impeller. 